Downtown’s Cortlandt Street R train station has a surprising old New York secret: mosaic tablets telling riders how to get to the Hudson Tubes—one of the early 1900s name for today’s PATH train tunnels.

Until the late 1960s, the Hudson Terminal, which took riders through the Hudson Tubes to points in Hoboken and beyond, was located above ground near Cortlandt Street.

There are regular subway signs, and then there are the ones that give clear directions—in these cases, using names no longer widely used.

The Port Authority Building, the Art Deco structure built in 1932 that stretches from 14th to 15th Streets on Eighth Avenue, must have been important; it scored its own sign in the station at that corner.

Google bought it in 2010, and it now serves as their famous New York City headquarters. I wonder what old-school Port Authority employees would think of the trick doors in the library and Lego play area.

It’s been more than a year since this old-school sign was uncovered after the removal of a newsstand in front of a subway entrance at Sixth Avenue and West Fourth Street (Gothamist scored the details in September 2011.)

Amazingly, the MTA hasn’t yet covered the slightly tattered but very charming sign. Could it be here to stay—a ghost from New York’s transit past reminding riders that the A, C, and E used to be part of the Independent Subway System, opened in 1932?